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Finding the Third Proportional to 70.17 and 78.05

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Solution

The third proportional to 70.17 and 78.05 is: 86.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.17 : 78.05 = 78.05 : x
  2. Step 2: Convert to fraction form
    70.17/78.05 = 78.05/x
  3. Step 3: Cross multiply
    70.17x = 78.05 × 78.05
  4. Step 4: Simplify right side
    70.17x = 6,091.31
  5. Step 5: Solve for x
    x = 6,091.31/70.17
  6. Step 6: Final answer
    x = 86.81

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Why These Related Problems?

These problems maintain the same ratio (1.11) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.